1. Field of the Invention This invention pertains to electrically powered vehicles and more particularly to interactive electrically powered toy vehicles.
2. Prior Art
Electrically powered toy vehicles are well known in the prior art. Typically, such vehicles incorporate a power supply, e.g. a battery, a motor driving a wheel pair, and a steering mechanism. Vehicle direction and speed are determined by proper control of the motor and steering mechanism. These controls may be on the vehicle itself or, in more advanced designs, on a remote controller which communicates control signals to the vehicle via wireless rf transmission.
U.S. Pat. No. 4,334,221 teaches a controller capable of remotely controlling a plurality of vehicles and discloses an approach for avoiding interference between one controller and another. As described in that patent, each controller repetitively transmits low duty-cycle command bursts containing an identity code and steering and speed commands for the controlled vehicle. The controllers transmit their command bursts asynchronously. Accordingly, due to the low duty-cycle of the transmissions, a high probability exists for non-interference even when several controllers are simultaneously operated with each controlling several vehicles. Each vehicle attempts to match any incoming command burst with a standard including an identity code unique to that vehicle. If a command burst is correct in every respect, including its identity code, the steering and speed commands therein are stored in the vehicle and executed until a new correct burst is received. Command bursts which are not correct in every respect are ignored whereupon the previously stored commands are executed.
While this arrangement is effective for controlling the movement of a plurality of vehicles, there is no interaction between the vehicles, and it is anticipated that the ability to control the movement of a plurality of vehicles with a single controller will prove insufficient to maintain interest in the product. At best, the vehicles can be raced, but it is difficult to preceive how a single controller can effectively race a plurality of vehicles when the controller can only address a single vehicle at a time.